The person beside you should not have to compete with a phone for the end of their sentence.

A glance at a screen mid-sentence delivers a message the words never do. It says the conversation is being ranked, live, against whatever arrived, and the person watching adjusts by getting shorter and less honest. Most of this happens below the level of anyone deciding anything. The habit is strong enough that people do it while genuinely wanting to listen.

Put the phone somewhere you cannot see it when someone starts talking, rather than face down beside you. Let the sentence finish before you do anything else.